Handle incoming terminating body payload
Unify stream element and stream end handling
Unify stream (re)start and stream event handling
Fix overwriting hold/wait values on stream restart
Extract stream event handling into function
Name requests constant as DEFAULT_REQUESTS
Step 1: handle requests in order
Introduce event_tag() type
Store events for deferred (in-order) processing
Process deferred events
Signal terminal condition on invalid request id
Suppress errors from predicates